How else could you do it?
Remember - Cloud Atlas is effectively about a single set of characters who are reborn - so you kinda need the same actor each time. Otherwise it is just a set of different, unrelated stories.
The whole conceit of the film is that they are visually recognisable as the same person each time.
The alternative (which you are perhaps arguing for) is to whitewash the film and rewrite it - so all the 'rebirths' occur with the same ethnic group, to match the actors.
Is there an alternative?
Mac
You want one, I'll give you other alternatives than 1:
1. Body swapping: These types of films are still popular in the US and Canada. You give them body language tells and it's all fine. They've done it with men and women, old and young.
Why can't you WRITE the screenplay to do just that. Give the actors all "tells" on their characters. The one soul has tells. Isn't that what people say... that who you are doesn't fundamentally change and certain factors tell you who that person is?
But God forbid, you should actually *trust* your audience, talent, directing and acting to pull it off. You'd just have to *write* it really well to pull it off as "character" rather than "labels for character" without preaching color blind.
2. You don't have to whitewash them, you could make them all of color...
No one really thinks of that, do they? The default must be white.
3. Remember, it's an adaptation, and you can sometimes do better than the source material, which means some licenses. Think ahead.
4. Not make it a movie. There are thousands of other subjects you can get to without shooting yourself in the foot.
It's like Victoria Foyt's novel should be made into a movie. You just don't do it.
Personally I prefer 1 or 4. 2 as a compromise and an empowerment statement and 3 as can't do anything with this, but not a strong enough writer to get over it.
There are other tricks you can pull off which have been used in other reincarnation movies. The so-called mirror trick, the dreams trick, and so on. You can switch actors and have them see glimpses of their past selves. If you need examples...
What Dreams May Come starring Robin Williams. Though there was reincarnation, due to the writing you could tell that the end had the two main characters reincarnated again. And that was a trippy movie that kinda was like Dante's Inferno aspects to it. (
Photographing Fairies also could be used to create the feel and landscape.)
All of Me (1984) uses a mirror to establish the other "soul", writing, story cues and acting to pull it off.
None of these deal with race, but you certainly can use the conventions in them to establish different souls and *study* them. After all, All of Me's concept was stolen and recreated for Mr. Jekll and Mrs. Hyde (which was lousy, but see, it recycled) And then stolen again for Me Two. And then recycled for the Robert Downey Jr. Movie, Hearts and Souls. I'm sure there is an older one before All of Me, but it's the earliest one I can remember.
With all that precedent, why *can't* they use those cues? It's a movie. They have more flexibility than a book visually.
I think it *can* be done, and it's been done numerous times with reflections, water, etc. There is plenty of precedent and it's even been done well in shoddy/crappy movies that make me want to find a wall to numb the pain from the *rest* of the story. Even Asian dramas manage to pull it off with different actors and story writing. Some trippy ones, too.
This is why you should study your genre and techniques before embarking otherwise you resort to cheap, ineffective and stupid methods like trying to justify [color]-face. There are ways to do it more gracefully. Use them.